Sensitized photographic emulsions



J. J. JENNEN ET Al. 2,544,322

SENSITIZED PHOTOGRAPHIC EMULSIONS Filed May 17, 1940 Marh 6, 1951 l. 40o 500 600 700/f/J Jaco Jaw/f JMW/l WWU/fer Mmm@ Patented Mar. 6, 1951 UNITED ,"ST'ATES PATENT OFFICE 2,544,322 SENSITIZED `PHOTOGRAPHIC' EMULSIONS 1 Jacob Josef Jennen,.Dilsen, and Walter Michaelis, Y Brussels, Belgium,assgnors, bymesne assignments, to BelaGaspar, Beverly Hills, Calif.

'ApplicationMay 17, 1940, Serial No. 335,854 .In Great Britain April 24, 1939 15' Claims.

dyes and `dyes of..similar ,structureaand more v 2 in which the hydrogen atoms may be substituted.

In the above formula:

A is a hetero atom vother than a nitrogen atom in an atom chain of a ringsystem;

particularly to dyes which are useful as sen- 5 sitizers for photographic silver halide emulsions. 1;; s aanlggarbon radlcal These dyes are widely' employeddn the art of photography and` color photography and a great eaf'rlgozza i 84(1)? 3 or n and m a e 1 number of cyamne dyes lsocyanme dyes pseuqo' R3 is a hydrocarbon radical an atom chain in- Cyamne dyes Carbocyanm? dyes aind'polymethme lo cluding three atoms which close a 5-memdyes havmg longer methmet @hams art? already bered hetero ring with Ya corbon atom of the known. These dyes are qua ernary sal s derived from cyclic ammonium bases in which there is gnfofmcrlnaltonetc lrlllnlo a pentavalentnitrogen atomsingle bound to to the other neghbourmg ring atom of a' hetero' of carbon atoms between the two nitrogen cyclic ring whilst the `fourth. valency of' the Sagl@ a. tapestries; site ra ica, he hva ency of e ni rogen a om ber of carbon atoms. The general forbeing 1n ionogene l1nkage with an` amon. 20 num The present invention relates tothe manufacgli? may also be represented m lts tautomelflc ture of methine dyes and polymethine dyes in t which the heterocyclic ring includes bothV a A Il nitrogen atom and another` hetero-atom such as K C=CH GH=(C4+1H2+2 N sulphur and in which a valencymof the lnitrogen 25 N/ y Xff l atom is linked not to an aliphatic butto a subl stituent cyclic carbon atom andmore particu- R1 larly -to photographic silverV halide .emulsions as indicated graphically in the examples. sensitized with such dye orA dyes. Whereas the I n theiollowin exam les, some of the known formu-19e of sensmzmg dyes'^ha,ve *been 'draft-gd 30 methods for progucing Icolyes of the above gen- Somellmes' broad' enough" to" mludef a Cycho eral formula are applied to` thev treatment of substituent at the nitrogen atom, 1t does not apthe N arylated quatemary Salts y the term pear. .that thpse dyes and more partl'ularly N-arylated Quaternary salts being intended to Sensmzmg thxazole dyes carrymg Sud? Supsm" include also compounds in which cyclic radicals tuenjs; have ben prepared or used m hght' 35 other than aromatic aryl radicals are linked to sensitive emulsions. The dyes Acan be prepared the nitrogen atom by treating. Narylai-'ed Quaternary Salts of a Example 1.--1 gram of 2.4-dimethyl-3-phenylheierocychc 'mtriogen base" the Img atom of thiazolium iodide (prepared according to the whichv includes another hetero atom such as sul- Journal of the American Chemical Society 1935 phur-and which carries. a methyl group in ortho n l0 page 1881 or to Berichte der Deutschen them-,- position to thepcyclicvmtrogen atom (or'the corischen Geseuschaft v01 69/1, page 221) and 5 respondmg methylene bases) py 'the mei-hogs grm of pdimethylaminobenzaldehyde is disknOWn-to be capable 0.f' .Convertmg htero'cychc solved by warming in 7 ccs. of ethyl alcohol. 'nitrogen bases contammg a reactwe methyl 1'7 grm of piperidine is then added and the group in a-position to a cyclic nitrogen atom 45 mixtureis reuXed for an hour.

(or the corresportdmg methylene bases) *into After cooling, ether is added, and thereupon dyes of the followmg generalformula: an orange-red dye separates out, which is dis- A* 1"3 solved by heating in a lime ethm amohol. on K Y, c-oHe-foH-:cCnoHwm-N cooling this solution, crystals with greenish lustre .N y 11h 50 are formed. The dye, dissolved in Water with X the addition of a small quantity of methyl alcohol has an absorption maximum at about 485Mo.

Its formula is probably that of the 2-dimethy1- aminostyryl 3 phenyl-4-methyl-thiazolium io- CH3 H.

A silver halide emulsion layer is sensitized to green light by the addition of the dye and then shows a maximum of sensitivity at about 450ml and another maximum at about 540ML.

Example 2.-3 grins. of the 2.4-dimethyl-N- phenyl-thiazolium iodide are heated with 3 grins. of N-methyl-a-thioquinolone-methyl-iodide and ccs. of dry pyridine in an oil bath at 120 C. for 11/2 hours. The addition of water to the cooled mixture results in the precipitation of a dye, having an absorption maximum in a methyl-alcoholic solution at about 482ml. Its formula is probably that of the 1methyl3phenyl4 methyl-thiazclo-pseudo-cyanine iodide:

S \C.H

(ULCHS Example 4.-4 ccs. of dry pyridine, .3 grm. of 2.4-dimethyl-3-phenyl-thiazolium iodide and .5 cc. of orthoformic acid ethyl ester are heated at about 120 C. for about two hours. A magenta dye is obtained which can be precipitated from 'the solution by the addition of ether. The dye is probably the 3.3'-diphenyl-4-4-dimethyl-thazolo carbocyanine iodide of the formula: raf-c s s -c-H CH3- -CH=CH-CH= -CHs Absorption (maximum) in methyl-alcoholic solutOIl Ca. 560ML.

Example 5.-3 grms. of dry p-chloro-thicacetanilide and 3 ccs. of chloroacetone are heated for about 10 minutes on a water bath. 50 ccs. ether are then added to the mixture and the whole is allowed to stand for several hours. The ether is decanted and the excess of chloro-acetone is removed by washing with ether. The raw product is heated for about 8 hours with 4.4 grms. ethyl toluenesulphonate and dissolved thereafter in 10 ccs. of dry pyridine. This solution is boiled with 3 ccs. orthoformic acid ethyl ester for about 45 minutes; after the addition of ether the solution is allowed to stand for several hours, preferably at 0 C. The liquid is decanted and the residue dissolved in methanol and precipitated again with ether. This may be done several times, whereafter the product is boiled with water and filtered. Green crystals of a metallic lustre are obtained, which are believed to be the 3.3di(pchlorophenyl) 4.4dimethylthazolo carbocyanine toluene-sulphonate of the formula:

Absorption in methylalcoholic solution ca. 560ml (max).

Example 6'.-In the foregoing examples the thiazol ring or rings in the resulting dyes are of the simple thiazole type Void of ortho condensed rings. A benzothiazoliurn cyanine dye may be prepared as follows: 12.5 grins. acetyl-diphenylamine-are dissolved in ccs. pyridine, 6 grms. phosphorus pentasulphide are added and the whole is stirred for 12 hours at 110 C. The upper light yellow layer is decanted off and the thioamide contained therein is precipitated with hydrochloric acid, ltered oil' by suction and recrystallised from alcohol. The compound which has a melting point of 112 C. is identical with the thioacetyl diphenylamine prepared by Bernthsen from carbon disulphide and diphenyl acetamidine (Annalen der Chemie, vol. 192, page 39).

6.8 grms. of the thioacetyl diphenylamine (N,N diphenylthioacetamide) thus obtained are dissolved in 30 ccs. chloroform and a solution of 4.8 grins. bromine in 10 ccs. chloroform is added in drops, the whole being cooled during this operation. The light yellow color of the solution changes to a dark brown and meanwhile hydrobromic acid is formed. After the mixture has been allowed to stand for two hours the chloroform is distilled off. The base is dissolved in acetone, freed of an undissolved grey powder by filtering oi this by-product; and the acetone is evaporated. A brown oil remains and this is dissolved in 50 ccs. acetic anhydride. Thereupon, 5 ccs. triethyl-ortho-formate are added and the whole is refluxed for 20 minutes. After cooling, 500 ccs. diethyl ether are added, the solution is kept in ice water for about 12 hours and then the precipitated dye is ltered off and washed with ether. It is believed to be 2.2-

diphenyl-thio -carbo-'cyanine acetate; and: the 1reaction is believed rto' proceed -as follows As will be seen :fromthe aboveliormulaethe nitrogen atomv in.. atleast Aone 'of v.the heterocyclic vrings ,ofthe .dye molecule is Llinked ,to a phenyl group. L By the use Yof lappropriate starting materials, such .as the N-tln'o-acetyl compounds derived from naphthylamine, p-iodoaniline, amino-pyridine vrst .converted by condensation with chloro-acetone linto L inl-substituted 2.4-

`dirnethyl-thiazolium salts andi by usi.ng.` .these compounds .in theprocess. instead (E24-'dimethyl- N-phenyl-thiazolium .iodideY employed ,in the above examples, there are obtained dyes "that contain.variouscyclic radicals, substituted Aor .unsubstituted, linked to the v.nitrogen atomof the hetero-cyclic ring.

It will be` lunderstoodtliatninsteadsof'they-sym- :metrical 1carmena-nineiV dyes;` VamsymmetricalzV dyes maybef prepared :and'it should further bef understood that the reference to certain: dyesfin'the examples is; not intended Vto. exclude similan'dyes, such as Aisocyanine dyes,;merocyanine dyes. vand polymethine dyes having arlonger polymethine chain. Merocyanine dyes may be: prepared, for example, by .refluxing for about 20 minutes: a solution of. .96, grm. 2.4-dimethy1-3-phenyl-thiazolium iodide and.;45 grrn. diphenyl-:formamidine in 5 ccs. acetic anhydride, separating the 2-.acetanilidovinyl3-phenyl-lemetliyl"thiazolium iodide from the. cooledV "solution :and:v condensing: the product with rhodanines, pyrazolones:andfthe like as follows: A solution of .17 'grrnt acetanilidovinyl phenyl methyl thiazolium` iodide and .03 grm. S-phenyl-rhodanine in 2 ccs. absolute ethylalcohol to which about .1 ccftriethylamine has been added, is reluxed for about 20 minutes and then,kept vforrseveral hours at a temperature ofnO"V C. The crystals rof the dye formed are Washed with ether. Thev dye which is'believ'ed to bathe 3 phenyl5 (3-phenyl-4- methyl- 2 thiazolylidene ethylidene) rhodanine has its absorption maximum at about 530W.. If instead of the phenyl-rhodanine .07 grm. 1- phenyl-B-mthyl-pyrazolone-(5) isused a dye is obtained which is precipitated from the solution by ether and which is washed with ether. The dye which is believed to be the S-methyl-lphenyl 4 (3 phenyl 4 methyl 2 `'thiazolylidene-ethylidene)A pyrazolone :(15) l has f its absorption Ymaximum at :about 480ML.

The dyes may be incorporatedin asilver .halide gelatin emulsion by 'bathing the .emulsion coating in an alcoholic or aqueous alcoholic' dye solution.` Or thedyesmay Abe incorporated in the emulsion, preferably into the finished emulsion before coatingthe samexon the. plategflm, paper or other support. For example, to a silver bromide-iodide, gelatinV emulsiony which has a silver content corresponding,r to 60V grms. silver nitrate per kilo emulsion and which has a speed of about 29 Sch. there is added a 1% ethylalcoholic solution of the sensitizing dye. 20 ccs. dye solution per kilo emulsion are used. The emulsions are then coated.

The sensitizing effect of the dyes is illustrated by the spectrograms of the accompanying drawing.4 Inlig. l the spectrograms 'of two dyes which carry acyclic substituent at the nitrogen atom and which are prepared according tothe preceding Examples 4. and 5 areshown in comparison with the spectrogram 'of the correspondying N-alkyl compound. InFig.' 2 the absorption curves of .these'thref-g'l dyes arefshown. 1' Fig. 3 shows the spectrogram of another N-arylated dye, prepared as described in'Examplel.' Fig'. 1 illustrates the improvementsobtainable by the introduction of a cyclic substituent into thedye molecule and the effect of substituents, such as chlorine, present in said cyclic radical. The choice of suitable substituents does not 'offer particular difliculties, as themore or less favorable influence `on the sensitizing properties is, in general; known for the-substituents usually employed.

A polymethine dye having a polymethinechain including more than three carbon atoms may be prepared by heating for about 5 minutes, .32 grin. 2.4-dimethyl-3-phenyl-thiazolium iodide with .14 grm. glutaconic dialdehyde .dianilide and .22 cc.

triethylamine in 4 ccs. absolute ethylalcohol, un-

til the solution has become bluegreen. Thedye crystallizes from the solution kept at low temperature for-several hours.

This application` fis: a continuation'--in-part` of 7 application Serial No. 331,462, filed April 24, 1940, now abandoned.

The novel N-aryl quaternary salts and novel method of making such salts as herein disclosed having been claimed in our copending application Serial No. 532,694, led April 25, 1944, now Patent No. 2,495,260, no claim is herein made to such salts or such method. Similarly the novel N-aryl thiazolium and thiazolylidene dyes as disclosed herein having been claimed in our copending application Serial No. 152,504, led March 28, 1950, no claim is herein made to such dyes per se.

We claim:

1. A photographic silver halide emulsion comprising a sensitizing dye which is selected from the group of sensitizing thiazolium dyes which have a phenyl radical directly linked to the quaternary nitrogen atom of the thiazolium ring.

2. A photographic material comprising a silver halide emulsion containing a dyestui serving to sensitize said silver halide emulsion corresponding with the formula wherein :N-X and in which X stands for an anion; Rz stands for a hydrocarbon radical; R3 stands for a member selected from the group consisting of hydrocarbon radicals, an atom chain including three atoms which serve to complete a 5-membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms, and an atom chain including two or four atoms which serve to complete a S-membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms; and stands for the atoms which serve to complete a heterocyclic radical.

3. A photographic material comprising a silver halide emulsion containing a dyestui serving to sensitize said silver halide emulsion corresponding with the formula A and B stand for hydrogen, alkyl or the carbon atoms to complete an aromatic ring;

in which X stands for an anion;

R2 stands for a hydrocarbon radical;

R3 stands for a member selected from the group consisting of hydrocarbon radicals, an atom chain including three atoms which serve to complete a -membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms, and an atom chain including two or four atoms which serve to complete a G-membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms; and

stands for the atoms which serve to complete a heterocyclic radical.

4. A photographic material comprising a silver halide emulsion containing a dyestul serving to sensitize said silver halide emulsion corresponding with the formula wherein A and B stand for hydrogen, alkyl or the carbon atoms to complete an aromatic ring;

R1 stands for a halogenated phenyl radical;

n stands for an integer selected from the group consisting of 0 and 1;

m stands for an integer selected from the group consisting of 0, 1, 2 and 3;

Y stands for a member selected from the group consisting of hydrogen and alkyl;

W stands for a radical selected from the group consisting of Rz l, Z =N-X and =-=o in which X stands for an anion;

R2 stands for a hydrocarbon radical;

Re, stands for a member selected from the group consisting of hydrocarbon radicals, an atom chain including three atoms which serve to complete a -membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms, and an atom chain including two or four atoms which serve to complete a -membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms; and

stands for the atoms which serve to complete a heterocyclic radical.

5. A photographic material comprising a silver halide emulsion containing a dyestul serving to 9 sensitize said silver halide emulsion corresponding with the formula A-C--S Y wherein the group in which X stands for an anion;

Rz stands for a hydrocarbon radical;

R3 stands for a member selected from the group consisting of hydrocarbon radicals, an atom chain including three atoms which serve to complete a 5membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms, and an atom chain including two or four atoms which serve to complete a 6-membered hetero ring with at least one carbon atom of the chain of carbon atoms between the two nitrogen atoms; and

Z stands for the atoms which serve to complete a heterocyclic radical.

6. A photographic silver halide emulsion sen sitized with a thiazolium cyanine dye having an aryl substituent on the N atom of the thiazole ring.

7. A photographic silver halide emulsion sensitized with a` thiazolium cyanine dye having a phenyl substituent on the N atom of the thiazole ring.

8. A photographic silver halide emulsion sensitized with a thiazolium cyanine dye having a halogenated phenyl substituent on the N atom of the thiazole ring.

9. A photographic silver halide emulsion sensitized with a thiazolium cyanine dye having a chlorophenyl substituent on the N atom of the thiazole ring.

10. A photographic silver halide emulsion sensitized with a dye of the following structural formula:

H-C--s In which X stands for an anion.

11. A photographic silver halide emulsion senv10 sitized with a dye of the following structural formula:

H Ij--s S--C-H oH- LJ\ IJ-CH=cH-0H=c IJ-CH :"""`x fidi 12. A photographic gelatino-silver-halide emulin which X stands for an anion.

sion sensitized with a dye selected from those represented by the following general formula:

eHs CeHs wherein X represents an acid radical.

13. A photographic gelatino-silver-halide emulsion sensitized with the dye of the following formula:

14. A photographic silver halide emulsion sensitized with a thiazolylidene merocyanine dye having an aryl substituent on the N-atom of the thiazolylidene ring.

15. A photographic silver halide emulsion sensitized with a thiazolylidene merocyanine dye having an aryl substituent on the N-atom of the thiazolylidene ring, the thiazolylidene radical comprising a simple thiazolylidene ring.

JACOB JOSEF J ENNEN. WALTER MICHAELIS.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 2,060,383 Schneider Nov. 10, 1936 2,196,162 Muller et al Apr. 2, 1940 2,199,542 AKonig May 7, 1940 2,233,511 Brooker et al Mar. 4, 1941 2,289,300 Wilmanns et al. July 7, 1942 2,317,357 Brooker et al Apr. 27, 1943 2,330,203 Brooker et al Sept. 28, 1943 FOREIGN PATENTS Number Country Date 505,979 Great Britain May 16, 1939 OTHER REFERENCES Doja: Chemical Reviews, Dec. 1932, pages 273-274.

Journal Chem. Soc., 1933, Part I, pages 189-191 (London).

Wall: History of Three-Color Photography, publ. 1924 by Amer. Phot.` Publ. Co., Boston, pages 211-214 and 217-219. 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION COMPRISING A SENSITIZING DYE WHICH IS SELECTED FROM THE GROUP OF SENSITIZING THIAZOLIUM DYES WHICH 